The fan-bellied leatherjacket skin was treated to extract collagen by chemical method. non-collagenous substances and the pigment in were removed with NaOH H2O2, respectively. Collagen extracted acetic acid. treatment extraction conditions optimized response surface methodology. concentrations, skin/solution ratios (g/ml) times surveyed. optimum remove as follows: concentration of at 0.15M, rat...

Gray-bellied Hawk, Accipiter poliogaster (Temmink, 1824), is a rare forest dwelling raptor in South America. This hawk migrates from Paraguay and northern Argentina (Misiones) the south to equator for winter. In Costa Rica this species has occasionally been recorded few localities. We present here new record disturbed area lowlands of country. may be vagrant or an occasional visitor Rica, it ex...